Packet data networks, including Internet protocol (IP) communication networks typically utilize domain name system or service (DNS) lookups in order to route calls within an enterprise or domain. Where a destination or endpoint is associated with a different enterprise or domain from that of the originating endpoint, the completion of the communication link requires that the destination domain be resolved. In a typical federated system, this requires a secure DNS lookup at a federation broker, typically located within the cloud. Provided the security requirements of the federation broker are met, the required routing information is returned to the originating enterprise or domain, and in particular to the communications server (e.g., a call server) handling the requested communication. The communication server can then apply the received information to complete the communication link to the endpoint in the other enterprise or domain.
Each time a communication link to an endpoint in a destination domain that is different than the originating domain is to be established, a request must be sent to the federation broker. However, this can be an expensive operation in terms of time and resources. Although dynamic DNS servers that maintain addressing information are known, such systems are limited to addressing local endpoints (i.e., entities within the same domain as the originating endpoint). In addition, existing systems are not capable of preventing or limiting requests for information to a federation broker that the federation broker has previously indicated is unavailable.